Vultures feeding on the carcass of a buffalo. Photograph: Anup Shah/Getty Images

Consider the vulture, a creature with a grim and unpleasant reputation. Its behaviour – gathering round dead or dying creatures before devouring them – has made it synonymous with ghoulish opportunism. Such a view is harsh, however, for the vulture serves a useful ecological function in many parts of the world. For example, the farms that cover India contain vast herds of cattle. Individual animals die and their corpses litter the landscape – though not for long. Vultures can clean up a cow carcass in minutes, leaving only bones.

Or at least, they used to. Several years ago, Indian farmers began using a new anti-inflammatory drug on their cattle. Traces proved to be lethal for vultures, which were killed in vast numbers. Dead cattle were left to rot with disastrous effects.

"There was an explosion in the population of wild dogs," says environmentalist Tony Juniper. "More dogs led to more dog bites and that caused more rabies infections among people." The disease killed thousands and cost the Indian government an estimated $30bn, he adds.

The fate of the Indian vulture makes it very clear that we tamper with the natural world at our peril. As the conservationist John Muir said: "When one tugs at a single thing in nature, you find it attached to the rest of the world." Certainly as an answer to the Pythonesque question posed by Juniper's title, the story – with many other tales garnered in this salutary, highly readable appreciation of the living world – tells a simple truth. Nature does a great deal for us.

For a start, the natural world is inspiring and has stimulated artists and writers through the ages. But it is not the spiritual importance of nature that concerns Juniper. It is its economic value that concerns him, a point that is often lost on big business. "There is a view that economic development is held back, and growth slowed, if we insist on protecting nature, but nothing could be further from the truth."

In fact, nature underpins our productivity and our fecundity. It replenishes fresh water supplies and provides us with plants for food and pharmaceuticals. Peat bogs soak up rainwater that would otherwise cause flooding while mangroves protect shorelines from storms. The air we breathe is constantly recharged with oxygen and the carbon dioxide that we, and our factories, exhale is dealt with by nature.

Then there is the soil beneath our feet. A single hectare can store and filter enough water for 1,000 people, while more than 90% of our food is grown in soil (the sea provides the rest). Yet we strip trees from its surface and erode vast tracts without considering the consequences. The result wreaked destruction throughout history, leading to the loss of the Mayan, Easter Island and other civilisations. As Franklin Roosevelt remarked: "The nation that destroys its soil destroys itself." Yet there is no evidence we have learned that lesson, as the current destruction of Amazon and Indonesian rainforests testifies.

"No matter how clever our financial systems, impressive our rates of economic growth or sophisticated our technology, there is no place to move to should we degrade our biosphere to the point where it can no longer meet our needs and sustain our economies," warns Juniper. The solution is to see nature for what it really is: a controller of disease, a recycler of waste, and a mighty carbon capture and storage system. If we get that message, we might yet save ourselves.